Over the last decade the advent of higher throughput screening technologies such as automated patch clamp has alleviated a major bottleneck in early stage drug discovery for ion channels. We present data from the IonWorks® Barracuda™.

The system allows simultaneous and continuous measurement of ionic currents at 384 separate recording sites. The system is equipped with 384 individual patch-clamp amplifiers together with a 384-channel fluidic pipettor. Currents are measured measured in the perforated patch clamp configuration using a single hole (SH) or an array of 64 holes in each well, Population Patch Clamp™ (PPC) technology. Data presented include LGIC recordings of acid sensing ion channels (ASIC1a), as well as VGIC recordings of hERG channels. The ASIC1a and human hERG channels stably transfected in CHO cells were generously provided by ChanTest Corporation (Cleveland, Ohio).ASIC1a current responses were elicited by the application of pH 5.0 buffer. Concentration-dependence of ASIC1a channel responses were inhibition by benzamil and amiloride determined in two different PPC experiments and gave IC50 values of 2.857e-006 M (n=384), and 1.041e-005 M (n=384), respectively. Concentration-dependence of hERG channel inhibition was determined for 3 different compounds, cisapride, terfenadine and quinidine, in three different PPC experiments. These gave IC50 values of 7.972e-008 M (n=384), 4.070e-007 M (n= 384) and 1.924e-006 M (n= 384) respectively. Additional data will be presented from Ligand-Gated (LGIC) and 1 nACh,aVoltage-Gated (VGIC) ion channels, including, Nav1.5, Kv1.3, a-1 nACh and a-7 nACH, and GABA channels. With a throughput of over 10,000 data points per day the IonWorks® Barracuda™ is a high-throughput automated electrophysiology system suitable for the screening ligand-gated and voltage-gated ion channel targets.